Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 6 December - 12 December 2017

Agung | Bali (Indonesia) : Based on BNPB and PVMBG reports, the eruption at Agung continued during 6-12 December, with high seismicity and nighttime crater incandescence often visible. On 8 December at 0759 an event generated a dense ash plume that rose 2.1 km above the crater rim and drifted W. Minor amounts of ash were deposited on the flanks, and lapilli was reported in Temakung. An ash plume rose 3 km at 1457. The number of evacuees on 10 December was 70,079 (spread out in 237 shelters). Ash plumes rose as high as 2 km. Lahars were observed in a drainage originating on the flanks of Agung. An explosion at 0549 on 11 December generated a dense ash plume that rose 2.5 km and drifted W and NW. Multiple ash-plume events were observed during 11-12 December, with plumes rising 1.5 km above the crater rim. The Alert Level remained at 4 (on a scale of 1-4), and the exclusion zones continued at a general 8-km radius and 10 km in the NNE, SE, S, and SW directions.

Kanlaon | Philippines : PHIVOLCS reported that an approximately 10-minute-long, low-energy phreatic eruption at Kanlaon began at 0947 on 9 December. A plume of voluminous steam and dark ash rose 3-4 km above the summit vent. The event was heard as far away as La Castellana, Negros Occidental. Minor amounts of ash fell in Sitio Guintubdan, and barangays Ara-al, Sag-ang, and Ilihan. The eruption was preceded by the resumption of degassing at the summit crater at 0634, detectable as continuous low-energy tremor during periods when the summit was not visible; degassing was last observed September 2016. The Alert Level remained at 2 (on a scale of 0-5).

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Klyuchevskoy was identified in satellite images during 5-6 December. Ash plumes rose as high as 5.5 km (18,000 ft) a.s.l. and drifted about 180 km during 5-8 December. The Aviation colour Code remained at Orange.

Pacaya | Guatemala : INSIVUMEH reported that during 9-12 December Strombolian explosions at Pacaya’s Mackenney cone ejected material as high as 25 m above the main cone. Lava flows traveled 100 m NW towards Cerro Chino cone, and 75 m SE.

Shishaldin | Fox Islands (USA) : AVO increased the Aviation colour Code for Shishaldin to Orange and the Volcano Alert Level to Watch on 6 December following several weeks of increasing seismicity and pressure waves recorded by infrasound sensors. Continuous infrasound waves were detected for more than 10 hours on instruments located in Sand Point, ~230 km E. Steam emissions visible in satellite and webcam images during 5 and 8-12 December were rising hundreds of feet above the summit crater. The steam emissions were occasionally accompanied by infrasound signals indicating episodes of short-duration energetic gas emissions and/or small explosions.

Villarrica | Chile : On 10 December POVI reported that the surface of the lava lake in Villarrica’s crater was stable at 70 m below the crater rim. Ejected lava from the lake was not evident in images captured during the previous five days, and incandescence and seismicity slowly decreased.